def show_trace(res):
 	n = max(abs(min(res)),abs(max(res)),10)
	f_line = np.arange(-n,n,0.1)
	plt.plot(f_line, [x*x for x in f_line])
	plt.plot(res, [x*x for x in res],'-o')
	plt.xlabel('x')
	plt.ylabel('f(x)')
	plt.show()
show_trace(res)
